Temperature is a variable that determine the flavor of the beer. The temperature of the beer will determine whether it taste crisp or harsh. Even if you use the best ingredients and follow the recipe perfect, if the yeast isnt at the correct temperature to work optimal, the beer will have the incorrect flavor profile.
A few degree off in the proper temperature for several day can transform a balanced beer into one that tastes like solvent or butter. Knowing the different temperature ranges that the yeast can withstand and function in is essential knowledge in the brewing process. The temperature chart demonstrate the different temperatures that the beer will be exposed to, from cold to hot, and the reason for each particular zone.
How Temperature Affects Beer Flavor
The cold crash temperatures will be at the bottom of the chart since these temperatures will help drop the yeast and haze out of the liquid. Below that will be the lager temperature range since lager yeast work slowly and produces best when exposed to lager yeast temperatures. The ale band is a broad temperature range since most ale yeast work optimally in the middle of the band.
The wild and sour temperatures are higher since these wild yeasts will produce acidic notes in warmer temperature. However, if the temperature go above the wild and sour zone, the yeast will become stressed and will produce harsh alcohol in the beer. Different yeast families requires certain temperature ranges to function since each type of yeast has evolved to work best in a specific environment.
Ale yeast will produce fruity ester when fermented within its ideal temperature range. Lager yeast need to be kept in a cold range to remain clean and will sink to the bottom of the fermenting liquid. The Belgian yeast strain will produce more spicy character at warmer temperatures so altering the temperature will alter the yeasts flavor.
The wild yeasts that live in warmer temperatures will produce the same when brewed with these yeast. Therefore, if the beer maker knows which type of yeast will be used, they can ensure that the temperature range is within the yeasts ideal range to remove guesswork in the brewing process. Each type of beer have its ideal temperature range because the temperatures used to brew them define the flavor profile of the beer.
A Czech pilsner requires the lager yeast temperatures to brew the beer to achieve the crisp taste that this beer is known for. An American pale ale contain hops, so the temperature should be low enough for the flavor of the hops to be the primary flavor in the finished brew. Any shift in the temperature of wheat beer will change the balance of the banana and clove flavor in the beer.
Similarly, Belgian beer flavors work best if the temperature rise after the fermentation of the beer since this encourage the yeast to produce the desired ester and phenol. Therefore, the beer style are grouped on the chart by the temperatures at which they work best. Fermentation passes through different stage with different temperature requirement.
The initial hours of fermentation require that the temperature be stable for the yeast to settle into the beer. Fermentation itself will produce heat in the initial hour that will raise the temperature of the wort several degree above the room temperature. Monitoring the temperature of the wort is essential as high wort temperatures can introduce off-flavors to the beer.
The later stage of fermentation require the beer to be warmed to assist the yeast in absorbing the last of the compound in the beer, as otherwise the beer might taste like butter or green apples. Cold conditioning allow for the beer to become clear and for the flavor of the beer to integrate before it is packaged into bottle or kegs. Most temperature problem that can occur during the brewing process are preventable with the proper step.
One of the most common problem is diacetyl, created when the temperature is too cold for the yeast to complete its fermentation task. Fusel alcohol will form if the brewing temperature is too hot for the yeast and stresses the yeast cell. Green apple note are created in beer if it is packaged while the yeast is still performing its last fermentation step.
If the yeast is prevented from creating these flaw by understanding the temperature range that the yeast prefers and measuring the wort temperature, then the batch of beer can be saved. Additionally, making any necessary temperature adjustment to the fermentation process early in the brewing stage allows enough time to make any necessary adjustment to prevent the damage that can be done to the batch of beer once it has begun. By following these step, the temperature problem can be solved.
By monitoring the temperature requirement of the yeast throughout the brewing stage, the quality of the beer batch can become more predictable. By understanding the temperature requirement for a specific type of yeast, that knowledge can be used to formulate the flavor of the beer. The temperature chart allow beer maker to understand the biology of the yeast strain being used to brew their beer.